During flight, an aircraft may be subject to the impingement of particles on its various external surfaces, which leave an electrical charge on the aircraft due to either a triboelectric process or charged particle interactions, particularly while flying through rain, snow, dust or clouds. Triboelectric charging is a result of charge build up due to the impingement of particles on a surface. Precipitation static or “p-static” charging is a result of both triboelectric charging and the charge build up on surfaces intercepting charged particles and/or regions. Both types of charging may be removed by using various types of discharge devices. The accumulation and discharge of precipitation or p-static may lead to disruptions in RF (radio frequency) radio communication and other undesirable effects. The term p-static as used herein means charge build up due to either triboelectric or precipitation processes.
P-static sensors have been developed for use on aircraft that provide a quantitative measure of the level of charge build up due to tribelectric or precipitation processes, however these sensors have been primarily used to perform controlled tests in which p-static levels are measured during aircraft certification processes required by regulatory authorities. However, existing p-static sensors may not be capable of measuring p-static to higher performance standards required by regulatory authorities for new applications, such as for composite aircraft.
Accordingly, there is a need for a method and device for measuring charge build up that may provide high levels of accuracy and which are suitable for use in new applications on aircraft. There is also a need for a p-static sensor that may be permanently installed on an aircraft to measure charge build up for purposes of controlling and/or monitoring various onboard flight systems.